The magic is in the _init_completion function which is defined in the bash_completion file of the bash-completion package.

There's no easy way out. If you want sensible fancy completion in bash, install the bash-completion package. Then define a function:

. /etc/bash_completion
_my_mysql () {
  local cur prev words cword
  _init_completion || return
  COMPREPLY=($(compgen -W 'firstdatabase databasetwo etc' "$cur"))
}
complete -F _my_mysql mysql

The magic is in the _init_completion function which is defined in the bash_completion file of the bash-completion package.

There's no easy way out. If you want sensible fancy completion in bash, install the bash-completion package. Then define a function:

. /etc/bash_completion
_my_mysql () {
  local cur prev words cword
  _init_completion || return
  COMPREPLY=($(compgen -W 'firstdatabase databasetwo etc' "$cur"))
}
complete -F _my_mysql mysql